Does an i-phone have to be "active" to suffice as a screen device for a DJI Mavic, or mini-mavic? Can it just be your or someone else's old i-phone with the card removed, but still in working order? No need to place or receive a call, but just use it as a viewing device for the little DJI drones.

I read in reviews that some are commenting that their phone needs to be removed from it's protective case to fit in the drone remote control screen holder.

I'm not even sure if used i-phone sell, or what is their value?

Any experiences here?